another 3.7 oil pressure question.

[ericcarr2000]

Ok, After replacing my oil pressure sending unit on my merc, I noticed that my oil pressure really wasn't where it should be, I know it is within specs, the 15 PSI @ 2000 R.P.M.'s, but im really not comfortable operating it at that level. The motor only has 106 hours on a blueprinted engine which I replaced back a few years ago. I took her out last night and everything seemed fine, that was until I went to W.O.T for a good length of time, about 10 minutes. After backing off of W.O.T. and putting her back in neutral I noticed the pressure dropped to a dangerous 10 or so P.S.I.'s. After running about 15 minutes or so in and around the 1700 R.P.M. range and then backing off the throttle and putting her in neutral, I had noticed the pressure dropped to about the 20 P.S.I. mark. Another thing is at W.O.T. the pressure was at a steady 40 P.S.I.
Am I jumping the gun so to speak when being concerned with the pressure after being @ W.O.T.?
Let me know your thoughts.
I know I am re-posting this problem from another post, but after hitting a brick wall on that one I Thought I'd try it again after I replaced the sending unit.

 

[Bondo]

Re: another 3.7 oil pressure question.

Ok, After replacing my oil pressure sending unit on my merc, I noticed that my oil pressure really wasn't where it should be, I know it is within specs, the 15 PSI @ 2000 R.P.M.'s, but im really not comfortable operating it at that level. The motor only has 106 hours on a blueprinted engine which I replaced back a few years ago. I took her out last night and everything seemed fine, that was until I went to W.O.T for a good length of time, about 10 minutes. After backing off of W.O.T. and putting her back in neutral I noticed the pressure dropped to a dangerous 10 or so P.S.I.'s. After running about 15 minutes or so in and around the 1700 R.P.M. range and then backing off the throttle and putting her in neutral, I had noticed the pressure dropped to about the 20 P.S.I. mark. Another thing is at W.O.T. the pressure was at a steady 40 P.S.I.
Am I jumping the gun so to speak when being concerned with the pressure after being @ W.O.T.?
Let me know your thoughts.
I know I am re-posting this problem from another post, but after hitting a brick wall on that one I Thought I'd try it again after I replaced the sending unit.

Ayuh,... Have ya cross-checked the eletric gauge, with a mechanical gauge,..??

The fact ya ran the snot out of it, Heats the oil, causin' the drop in idle pressure,...

Oil pressure is a function of bearin' clearances,... I wouldn't be worried at this point,...

 

[ericcarr2000]

Re: another 3.7 oil pressure question.

Hi Bondo, Im getting ready to head up to her here in a little bit to hook up a mechanical gauge to her. What im going to try to do is hook the mechanical gauge directly to the block and have the sending unit hooked up so I can monitor the differences between the two, if there are any..
Ill let you know my findings later on...

Ayuh,... Have ya cross-checked the eletric gauge, with a mechanical gauge,..??

The fact ya ran the snot out of it, Heats the oil, causin' the drop in idle pressure,...

Oil pressure is a function of bearin' clearances,... I wouldn't be worried at this point,...

 

[nola mike]

Re: another 3.7 oil pressure question.

the pressure dropped to a dangerous 10 or so P.S.I.'s.

According to who? not merc. You didn't hit a brick wall on the other post. You have nothing wrong. Read your sig.

 

[ericcarr2000]

Re: another 3.7 oil pressure question.

Actually I did find out I have an issue. I installed an adapter on the motor so I could install the mechanical gauge along with the 'New" sending unit....At this point the gauge on the dash would only go as high as 20 pounds, even at W.O.T. While the mechanical gauge which was on the side of the motor was reading around 70 pounds at W.O.T. and around the 40 mark at idle.....Thank god looks like my problem all along was the gauge which I installed new last year, believe it or not...
I think im going to leave that mechanical gauge mounted on the side of the motor and run it like that for now....
Thanks again for the help...

According to who? not merc. You didn't hit a brick wall on the other post. You have nothing wrong. Read your sig.

 

[ericcarr2000]

Re: another 3.7 oil pressure question.

Oh yeah, one question I do have is with me having two different gauges on her could that give a false reading on one of them?

 

[Bondo]

Re: another 3.7 oil pressure question.

Oh yeah, one question I do have is with me having two different gauges on her could that give a false reading on one of them?

Nope,...

Ya didn't use tape to seal the threads of the new sender, did ya,..??

 

[ericcarr2000]

Re: another 3.7 oil pressure question.

Actually I did use some Teflon tape to seal them..I did make sure the tape did NOT go on the bottom of the fitting though.

Nope,...

Ya didn't use tape to seal the threads of the new sender, did ya,..??

 

[Bondo]

Re: another 3.7 oil pressure question.

Actually I did use some Teflon tape to seal them..I did make sure the tape did NOT go on the bottom of the fitting though.

Ayuh,... It's blockin' the ground path,.... Bad ground, wrong readin's,...

use a Paste,...

 

[ericcarr2000]

Re: another 3.7 oil pressure question.

really, no kidding? Didn't know that, thanks

Ayuh,... It's blockin' the ground path,.... Bad ground, wrong readin's,...

use a Paste,...